If you want to build your complete environment, you need to download the latest Poky stable release 3.2.x ‘Purple’ (latest) and extract it to ~/devel. Make sure you have a broadband connection and atleast 3G of disk space as the scripts will fetch, build everything from toolchains, kernels, user space applications. Follow the Poky handbook which is very well documented. Supported reference platforms include (to mention a few):